### Abstract

The definition of the scattering cross section for the pressure field scattered by a rough interface uses the underlying assumption that the ensonified area does not affect its shape. This assumptions holds so long as the incident field is a good approximation of a plane wave, which situation occurs when the ensonified area is large compared to a wavelength. In the opposite situation, when the ensonified dimensions approaches a wavelength, the incident plane wave assumption does not hold and the cross section can depart from modeled behavior. This research uses the Perturbation approximation to derive a model for the low grazing-angle behavior of the scattering cross section. The primary results are 1) the appearance of an additive Lambertian term, and 2) a separation of scales imposed by the acoustic resolution. This separation can then be used as a criterion for the application of the composite roughness model. Model results are checked against direct numerical solution of the governing integral equations. Implications for inversion of seafloor parameters based on acoustic scattering experiments is discussed.

Original language | English (US) |
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Article number | 070012 |

Journal | Proceedings of Meetings on Acoustics |

Volume | 19 |

DOIs | |

State | Published - Jun 19 2013 |

Event | 21st International Congress on Acoustics, ICA 2013 - 165th Meeting of the Acoustical Society of America - Montreal, QC, Canada Duration: Jun 2 2013 → Jun 7 2013 |

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### All Science Journal Classification (ASJC) codes

- Acoustics and Ultrasonics

### Cite this

*Proceedings of Meetings on Acoustics*,

*19*, [070012]. https://doi.org/10.1121/1.4800713

}

*Proceedings of Meetings on Acoustics*, vol. 19, 070012. https://doi.org/10.1121/1.4800713

**The impact of finite ensonified area on the scattering cross section.** / Olson, Derek R.; Lyons, Anthony.

Research output: Contribution to journal › Conference article

TY - JOUR

T1 - The impact of finite ensonified area on the scattering cross section

AU - Olson, Derek R.

AU - Lyons, Anthony

PY - 2013/6/19

Y1 - 2013/6/19

N2 - The definition of the scattering cross section for the pressure field scattered by a rough interface uses the underlying assumption that the ensonified area does not affect its shape. This assumptions holds so long as the incident field is a good approximation of a plane wave, which situation occurs when the ensonified area is large compared to a wavelength. In the opposite situation, when the ensonified dimensions approaches a wavelength, the incident plane wave assumption does not hold and the cross section can depart from modeled behavior. This research uses the Perturbation approximation to derive a model for the low grazing-angle behavior of the scattering cross section. The primary results are 1) the appearance of an additive Lambertian term, and 2) a separation of scales imposed by the acoustic resolution. This separation can then be used as a criterion for the application of the composite roughness model. Model results are checked against direct numerical solution of the governing integral equations. Implications for inversion of seafloor parameters based on acoustic scattering experiments is discussed.

AB - The definition of the scattering cross section for the pressure field scattered by a rough interface uses the underlying assumption that the ensonified area does not affect its shape. This assumptions holds so long as the incident field is a good approximation of a plane wave, which situation occurs when the ensonified area is large compared to a wavelength. In the opposite situation, when the ensonified dimensions approaches a wavelength, the incident plane wave assumption does not hold and the cross section can depart from modeled behavior. This research uses the Perturbation approximation to derive a model for the low grazing-angle behavior of the scattering cross section. The primary results are 1) the appearance of an additive Lambertian term, and 2) a separation of scales imposed by the acoustic resolution. This separation can then be used as a criterion for the application of the composite roughness model. Model results are checked against direct numerical solution of the governing integral equations. Implications for inversion of seafloor parameters based on acoustic scattering experiments is discussed.

UR - http://www.scopus.com/inward/record.url?scp=84878994339&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878994339&partnerID=8YFLogxK

U2 - 10.1121/1.4800713

DO - 10.1121/1.4800713

M3 - Conference article

VL - 19

JO - Proceedings of Meetings on Acoustics

JF - Proceedings of Meetings on Acoustics

SN - 1939-800X

M1 - 070012

ER -